Will a cross-border trade war force Justin Trudeau to finally call a halt to unconstitutional actions that threaten not just a pipeline, but a country?

Alberta Premier Rachel Notley announces on Tuesday Feb. 6, 2018 that Alberta will boycott all wine from British Columbia in response to the B.C. government's delay of the Trans Mountain pipeline expansion.Larry Wong/Postmedia

Alberta’s first volley in the great trade war with B.C. is an eye-catcher for sure. Premier Rachel Notley has decreed a ban on imports of B.C. wine. She told the Alberta Gaming and Liquor Commission to stop buying it.

In real economic terms, this is a peashooter aimed at the B.C. cannon. The loss to B.C. wineries would be about $70 million a year. The stalled pipeline deprives the Alberta treasury of $1.5 billion.

Hilarity on social media was inevitable. Some called it the Pinot Pipeline blockade. Others said, “Oh, no, we want Merlot.”

But this is a sharp first slap that Notley warns could lead to more action. It also instantly caught the country’s attention — what the hell’s going on out there?

The open trade warfare will certainly worry the federal Liberals, who have been trying to drift past the whole pipeline dispute by pretending it’s just a little spat between provinces, when the real issue is B.C.’s defiance of crucial federal authority over trade.

Notley is considering more measures unless Ottawa acts or B.C. withdraws its proposal to control diluted bitumen shipments.

She mentioned Tuesday that B.C. ships a heck of a lot of beer into Alberta. That ban could be next.

An infinitely more serious action, slowing down oil shipments through the current Kinder Morgan pipeline, appeals to many Albertans who want severe retaliation.

But that almost certainly won’t happen. Notley has vowed to take no step that would hurt Alberta workers and companies.

There will be no ban, however, on Albertans buying cases of wine in B.C. and bringing them back to Alberta in their vehicles. This will remain perfectly legal, unless you drink it while you’re driving.

The overall ban will be damaging, for sure, but likely not disastrous for the B.C. wine industry.

Al Drinkle, partner in the excellent Metrovino wine store, says many B.C. wineries can easily sell their entire production within the province.

He feels those domestic sales could even go up as Albertans drink their way through summer holidays in the Okanagan. Tourists could also buy more wine to bring home, knowing they can’t get it in Alberta.

But the ban isn’t trivial, either. The AGLC, with $70 million a year in purchases, is a big customer. The ban will be alarming and inconvenient to some big B.C. shippers.

Notley clearly doesn’t want to cause catastrophic damage to rival what B.C. Premier John Horgan is happy to inflict on Alberta. I thought she sounded uncomfortable announcing a measure that will hurt some people in a province many Albertans admire and enjoy.

But Notley rightly says that enough is enough. Albertans are sick of being the “unintended consequence” of other provinces’ NIMBY fears and prejudices.

She seemed to be referring to the Quebec-inspired death of the Energy East pipeline, as well as the B.C. government’s disregard for fair process and even the Canadian Constitution.

By late afternoon, Horgan was trying to rally British Columbians around the wine industry. It might work. Local patriotism is a powerful thing.

The Alberta NDP hopes, though, that residents of the B.C. interior, who generally favour the pipeline, will be furious at Horgan for triggering this trade war. One test will be the byelection set for Valentine’s Day in Kelowna-West, to fill the seat vacated by former Premier Christy Clark.

The deeper game for Notley is to flush out Prime Minister Justin Trudeau. Will a cross-border trade war force him to finally call a halt to unconstitutional actions that threaten not just a pipeline, but a country?